While I agree that you fit what you can afford into your budget, and style of car you drive or are building, that doesn't mean a shop has to compromise it's quality and "image" to suit a particular customers needs.
Let's say I painted 10 high end paint jobs that bring in 5 customers to get the same level of work. That is great right?
But one shoddy job for a cheap customer can scare away 100 potential customers.
On the flip side of that though is that I have seen shops that take care of "VIP" customers or celebrities better than the average customer. That's crap!
Whether you spend $100 or $10,000 at my place, you are important and are going to get the best I can do for that $100.